590 IF. A. E. V'--<s/iei- — Devmiidii Eoch of Coruaui/l. 



So far as I am aware, Mr. Worth's criticisms on my paper of 1891 

 are the only ones that have appeared in print. The title of the 

 paper is misleading, as De la Heche's descriptions merely furnished 

 the material, but the Devonian geology was derived from my own 

 work in South Devon, which gave the clue for separating his minor 

 subdivisions into widely different horizons. 



Mr. Upfield Green, in an article on the correlation of some Cornish 

 beds with the Gedimiian of Europe (in the August number of the 

 Geological Magazine), has pointed out my inadvertent use of 

 the term ' Gedinnien ' as applied to the Looe beds in 1900, but he 

 has overlooked their correlation with the Siegener Grauwacke in 

 the table of classification in the " Memoir on the Geology of the 

 country around Torquay " in 1903. He has also omitted to state 

 that Dr. Kayser first correlated them with the Taunusien in 1882.^ 

 Of this I was well aware, as Dr. Kayser had called attention to 

 the fact in a brochure in 1888 giving the results of a trip to the 

 North and South Devon Devonian in company with Professor 

 Gosselet and others under my guidance. In my paper of 1891 

 I suggested the correlation of the Grampound grits with the 

 Gedinnien; to this Mr. Green does not refer, although I gather 

 from his paper that he places them in the same group that I did 

 then, but hesitate to do now. 



In a general way I gather that Mr. Upfield Green places those 

 rocks between the Lizard district on the south and the St. Austell 

 granite on the north, which are not admittedly Silurian, in the 

 Gedinnian, including in that group the Mylor, Falmouth, and 

 Portscatho beds of Mr. Hill, and placing the Dartmouth slates at 

 the top. There is, however, one objection to this, viz., the assumed 

 continuity of the Dartmouth slates " through Ty wardreath and 

 St. Austell to St. Stephens as described by De la Beche." I, too, 

 assumed this continuity from De la Beche, but on investigating the 

 ground I found that the Dartmouth slates are cut oft" by a nearly 

 north and south fault near Tywardreath, and do not extend round 

 the St. Austell granite, either on the north or south margin, to 

 Watergate Bay. 



Mr. Upfield Green has raised a very interesting question in 

 claiming the non-Silurian rocks of South Cornwall as Gedinnien, 

 but there is no proof that these rocks are below the Dartmouth 

 slates. To entertain this suggestion the absence of Dartmouth 

 slates on the south of the St. Austell granite would have to be 

 explained by a very improbable change in character, or by a fault 

 between the Perran Perth and Pentuan coasts throwing Gedinnian 

 rocks on the south against the higher beds of the Meadfoot group 

 on the north. Without an acquaintance with the district west of 

 Grampound and Ladock I should not like to express any very 

 definite opinion. Mr. Upfield Green, no doubt inadvertently, states 

 that the Dartmouth slates may be traced " across the Start Peninsula 

 as far as Babbacombe, south of Dartmouth in Devonshire." This 



1 Jahrb. d. kgl. preuss. Laudosaustalt., p. 128, 1882. 



